Submesoscale coherent vortices in the deep Brazil Basin

• Main Author: Kassis, Patricia
• Format: Thesis
• Language: English
• Published: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution 2000
• Subjects: Eddies; Vortex-motion; North Atlantic Deep Water; North Atlantic
• Online Access: https://hdl.handle.net/1912/4189

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 2000 With Lagrangian and hydrographic data taken in the deep Brazil Basin, we identify several submesoscale coherent vortices (SCVs). These features contrast with SCV paradigms in that float data indicate approximately equal populations of cyclonic and anticyclonic vortices, and hydrographic data suggest that roughly half exhibit the convex lens shape generally associated with SCVs, while half are instead shaped like a concave lens, with isopycnal surfaces pinched together. There is some evidence that the vortex cores may be enriched in warm, salty North Atlantic Deep Water, suggesting formation in the north or northwest regions of the basin. Data is available from 153 floats which were ballasted for 2500 and 4000 db pressures. They tracked 34 eddies, which are believed to be roughly 30 km in diameter, and rotate with apparent periods of about 30 days. Many floats experienced formation or entrainment events, and destruction or detrainment events, near seamounts. This work was supported by the National Science Foundation, grants OCE 99-11148 and OCE 94-15509.